Here line current of given generator will directly applied to star connected load which is given in question itself,
from that we can say that this line current will flow through each phase of star connected load.
hence
phase voltage =line current of generator * impedance of phase
=20(5-4j)
phase voltage =100-j80

The problem states that a delta connected generator has a line current of 20A. A star connected load is applied across the terminals of the generator, with impedances of (5-j4) per phase. We need to find the phase voltage of the generator.

To solve this problem, we can follow these steps:

1. Convert the star connected load to an equivalent delta connected load.
2. Find the line voltage across the delta connected load.
3. Determine the phase voltage of the generator.

Let's go through each step in detail:

1. Convert the star connected load to an equivalent delta connected load:
- To convert a star connected load to a delta connected load, we use the following transformation:
Zdelta = Zstar / 3
- In this case, the impedances of the star connected load are (5-j4) per phase. So, the equivalent delta connected load impedance would be:
Zdelta = (5-j4) / 3

2. Find the line voltage across the delta connected load:
- The line voltage across the delta connected load is equal to the line current multiplied by the load impedance.
- In this case, the line current is given as 20A, and the load impedance per phase is (5-j4)/3. So, the line voltage across the delta connected load would be:
Vline = 20A * (5-j4)/3

3. Determine the phase voltage of the generator:
- The phase voltage of the generator is equal to the line voltage divided by the square root of 3.
- In this case, the line voltage across the delta connected load is Vline, which we calculated in the previous step. So, the phase voltage of the generator would be:
Vphase = Vline / √3

By following these steps, we can find the phase voltage of the generator.